==================================================================
BUG: KASAN: slab-use-after-free in find_endpoint+0x2a3/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1622
Read of size 1 at addr ffff888054af80e8 by task syz.3.2374/12392
CPU: 0 UID: 0 PID: 12392 Comm: syz.3.2374 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
find_endpoint+0x2a3/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1622
dummy_timer+0x500/0x3820 drivers/usb/gadget/udc/dummy_hcd.c:1894
__run_hrtimer kernel/time/hrtimer.c:2074 [inline]
__hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2131
hrtimer_run_softirq+0x1ca/0x360 kernel/time/hrtimer.c:2148
handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x16a/0x210 kernel/softirq.c:758
irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:221
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 76 1a 10 f6 48 89 df e8 fe 70 10 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 85 54 ff f5 65 48 83 3d f4 32 b6 09 00 74 16 5b
RSP: 0018:ffffc9000dfafa68 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff88801d031540 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff8e3e3b01 RDI: ffffffff8c625680
RBP: 0000000000000202 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffea0001f25e80
R13: ffffea000090b700 R14: ffff88801d0328c0 R15: ffffea0001daa000
spin_unlock_irqrestore include/linux/spinlock.h:425 [inline]
get_partial_node_bulk mm/slub.c:3878 [inline]
__refill_objects_node+0x2a7/0xab0 mm/slub.c:7279
refill_objects+0x58/0x410 mm/slub.c:7405
refill_sheaf mm/slub.c:2885 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
alloc_from_pcs mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:4984 [inline]
__kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
_kmalloc_noprof include/linux/slab.h:991 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
netlbl_secattr_alloc_noprof include/net/netlabel.h:385 [inline]
selinux_netlbl_sock_genattr+0xe7/0x4e0 security/selinux/netlabel.c:78
selinux_netlbl_socket_post_create+0xb0/0x1c0 security/selinux/netlabel.c:404
selinux_socket_post_create+0x368/0x7e0 security/selinux/hooks.c:5105
security_socket_post_create+0xaf/0x270 security/security.c:4215
__sock_create+0x70b/0x860 net/socket.c:1699
sock_create net/socket.c:1734 [inline]
__sys_socket_create net/socket.c:1771 [inline]
__sys_socket+0x14d/0x260 net/socket.c:1818
__do_sys_socket net/socket.c:1832 [inline]
__se_sys_socket net/socket.c:1830 [inline]
__x64_sys_socket+0x72/0xb0 net/socket.c:1830
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f546df9e559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f546edc7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007f546e225fa0 RCX: 00007f546df9e559
RDX: 0000000000000007 RSI: 0000000000000003 RDI: 000000000000000a
RBP: 00007f546e035ab8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f546e226038 R14: 00007f546e225fa0 R15: 00007ffe2cf98ea8
Allocated by task 10867:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5414 [inline]
__kmalloc_noprof+0x32f/0x840 mm/slub.c:5439
_kmalloc_noprof include/linux/slab.h:995 [inline]
usb_copy_descriptors+0xcd/0x320 drivers/usb/gadget/config.c:82
f_midi2_bind+0x1dad/0x2770 drivers/usb/gadget/function/f_midi2.c:2025
usb_add_function+0x219/0x890 drivers/usb/gadget/composite.c:333
configfs_composite_bind+0xd83/0x1960 drivers/usb/gadget/configfs.c:1802
gadget_bind_driver+0x28c/0xbf0 drivers/usb/gadget/udc/core.c:1662
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x210/0x460 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292
bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763
driver_register+0x1e2/0x360 drivers/base/driver.c:174
usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1752
gadget_dev_desc_UDC_store+0x1b0/0x2e0 drivers/usb/gadget/configfs.c:300
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 12342:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2748 [inline]
slab_free mm/slub.c:6509 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6802
usb_free_descriptors include/linux/usb/gadget.h:903 [inline]
usb_free_all_descriptors+0x81/0x1a0 drivers/usb/gadget/config.c:151
purge_configs_funcs+0x285/0x510 drivers/usb/gadget/configfs.c:1600
configfs_composite_unbind+0xae/0x210 drivers/usb/gadget/configfs.c:1846
gadget_unbind_driver+0x20c/0x4f0 drivers/usb/gadget/udc/core.c:1724
device_remove+0xcb/0x180 drivers/base/dd.c:616
__device_release_driver drivers/base/dd.c:1349 [inline]
device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372
driver_detach+0xd8/0x1b0 drivers/base/dd.c:1435
bus_remove_driver+0x13b/0x2e0 drivers/base/bus.c:832
driver_unregister+0x76/0xb0 drivers/base/driver.c:202
usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1784
unregister_gadget drivers/usb/gadget/configfs.c:263 [inline]
gadget_dev_desc_UDC_store+0x170/0x2e0 drivers/usb/gadget/configfs.c:290
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888054af8000
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 232 bytes inside of
freed 512-byte region [ffff888054af8000, ffff888054af8200)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54af8
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801d032c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801d032c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5604, tgid 5604 (syz-executor), ts 72772587898
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
prep_new_page mm/page_alloc.c:1879 [inline]
get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943
__alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436
alloc_slab_page mm/slub.c:3347 [inline]
allocate_slab mm/slub.c:3462 [inline]
new_slab+0xa9/0x6e0 mm/slub.c:3513
refill_objects+0xe3/0x410 mm/slub.c:7418
refill_sheaf mm/slub.c:2885 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
alloc_from_pcs mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:4984 [inline]
__kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
_kmalloc_noprof include/linux/slab.h:991 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
simple_xattrs_lazy_alloc.part.0+0x41/0x100 fs/xattr.c:1367
simple_xattrs_lazy_alloc fs/xattr.c:1364 [inline]
simple_xattr_add+0xe55/0x1340 fs/xattr.c:1671
shmem_initxattrs+0x1f0/0x650 mm/shmem.c:4237
security_inode_init_security+0x242/0x370 security/security.c:1370
shmem_mknod+0x2ce/0x480 mm/shmem.c:3841
shmem_mkdir+0x31/0x80 mm/shmem.c:3896
vfs_mkdir+0x364/0x850 fs/namei.c:5409
filename_mkdirat+0x48b/0x5e0 fs/namei.c:5442
__do_sys_mkdirat fs/namei.c:5463 [inline]
__se_sys_mkdirat fs/namei.c:5460 [inline]
__x64_sys_mkdirat+0x89/0xc0 fs/namei.c:5460
page last free pid 1 tgid 1 ts 14263113975 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1418 [inline]
free_pages_prepare+0x586/0xe00 mm/page_alloc.c:1463
__free_contig_range_common+0x14f/0x250 mm/page_alloc.c:7072
debug_vm_pgtable_free_huge_page mm/debug_vm_pgtable.c:980 [inline]
destroy_args+0xa8/0x7a0 mm/debug_vm_pgtable.c:993
debug_vm_pgtable+0x1d69/0x3490 mm/debug_vm_pgtable.c:1368
do_one_initcall+0x11c/0x6f0 init/main.c:1362
do_initcall_level init/main.c:1424 [inline]
do_initcalls init/main.c:1440 [inline]
do_basic_setup init/main.c:1460 [inline]
kernel_init_freeable+0x6ea/0x7b0 init/main.c:1675
kernel_init+0x21/0x1e0 init/main.c:1565
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff888054af7f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888054af8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888054af8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888054af8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888054af8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: f5 cmc
1: 53 push %rbx
2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi
7: 48 89 fb mov %rdi,%rbx
a: 48 83 c7 18 add $0x18,%rdi
e: e8 76 1a 10 f6 call 0xf6101a89
13: 48 89 df mov %rbx,%rdi
16: e8 fe 70 10 f6 call 0xf6107119
1b: f7 c5 00 02 00 00 test $0x200,%ebp
21: 75 23 jne 0x46
23: 9c pushf
24: 58 pop %rax
25: f6 c4 02 test $0x2,%ah
28: 75 37 jne 0x61
* 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction
2f: e8 85 54 ff f5 call 0xf5ff54b9
34: 65 48 83 3d f4 32 b6 cmpq $0x0,%gs:0x9b632f4(%rip) # 0x9b63331
3b: 09 00
3d: 74 16 je 0x55
3f: 5b pop %rbx